Improve behaviour if there is a selenium error

Old behaviour: tests would all try to run and fail because selenium
was broken.

New behaviour: beforeall hook fails correctly and we get just
one error telling us the problem.
Merge pull request #654 from scraperwiki/better-selenium-error

Improve behaviour if there is a selenium error
Only jump to datatables-view if status is set
Fix a couple more befores
Switch more befores to its
Fix integration test for fresh datasets

When visiting a fresh dataset, we now navigate to the dataset itself
rather than the view in a table tool.
Fixup against implementation
Make the URL consistent for the tests
Mark some tests @mayberacy